Frequently in buildings of modern construction, the ceiling is provided in the form of a grid or framework which is suspended from the slab of the floor above, or from rafters or joists of the building frame. Panels or tiles, e.g., of sound-absorbing material, are mounted in individual cells of the suspended grid. Lighting fixtures, heating, ventilating and air conditioning vents or grills and the like often are incorporated in such ceilings.
In commonly used ceiling suspension systems, the gridwork is assembled in place from largely pre-cut or pre-fabricated modules, with a certain amount of further cutting, bending, twisting and similar tailoring or modifying of elements being done by the assemblers on the site. It is not uncommon for suspended ceiling installers to work in pairs, on ladders or wheeled scaffolding, sometimes with an assistant for cutting some elements to length, opening cartons, inspecting and handing-up modules to be installed, and so forth.
Having had considerable experience with commercially available suspended ceiling systems, the present inventor has come to realize that the mechanical design of the elements of the systems now available embody shortcomings that render some installations considerably more difficult, time-consuming and expensive than fundamentally is necessary. In particular, the workers on ladders or scaffolding generally are called upon to perform manipulations by hand and with hand tools while working overhead, manipulations which are difficult and frustrating to perform in such an awkward orientation, and doubly so when something goes wrong and must be disassembled and redone. In fact, some popular ceiling systems are very mistake/change intolerant, so that if a later-noticed mistake made in the middle of a gridwork is to be remedied or a bent or defective element must be replaced or a change is mandated, much of the work that has already been done has to be taken down and redone. In fact, where bending, riveting, snapping together and similar comparatively irreversible manipulations are used for assembling the grid elements of such popular systems, it may be necessary to use a metal saw or cutters to sever the elements between joints, in the course of which much of what had been installed is destroyed and must be scrapped.